import java.util.ArrayList;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 17655
 * Date: 2025-03-24
 * Time: 18:16
 */
public class test6 {
    /**
     * 有26个字母a-z，找出所有字母的组合，a、b、c、ab、abc、ac、a~z都是一个组合(顺序无关)
     */
    public static void main(String[] args) {
        ArrayList<String> list = new ArrayList<>();
        for(char i ='a' ;i<'z';i++){
            String st = "";
            for(char j=i;j<'z';j++){
                st += j;
                list.add(st);
            }
        }
        for (String string:list){
            System.out.println(string);
        }
    }
}
